Called "Bobs," Robert is the middle boy known for being quick-tempered and sometimes thoughtless. Despite this, he is capable of bravery and has an adventurous spirit.

Nicknamed "Panther," Anthea is the older of the two girls, known for being kindhearted and tactful. She often mediates conflicts and calms her siblings down during tense moments.

Also known as "Pussy," Jane is noted for her honesty and hopeful nature. She is affectionate and often becomes upset when things go wrong but shows a caring side towards others.

The Lamb, whose real name is Hilary, is the youngest sibling and mainly serves as a catalyst for the children's adventures. As a two-year-old, he is both endearing and sometimes annoying to his older siblings.

The Psammead, also known as the Sand-fairy, is a grouchy and vain creature that grants the children's wishes. It often provides a sense of humor and wisdom, teaching the children lessons about their wishes.

Martha is the children's nursemaid, representing law and order with little imagination. While she is often oblivious to the children's magical adventures, she is kind-hearted and sympathetic.